Reinforced Railroad Tie

ABSTRACT

A track for a vehicle comprising at least one rail, a plurality of elongated ties supporting the rail, and a fastener for holding the rail to the ties is provided. At least one tie used in the track comprises a body formed at least partially of polymeric material, and an elongated reinforcement encapsulated within the body, the reinforcement having a top section having a top surface, a bottom section having a bottom surface, and a support section connecting the top section and the bottom section, the bottom section having a greater weight than the top section.

BACKGROUND

A railroad tie, cross tie, or railway sleeper is a rectangular object used as a bottom section for railroad tracks. Railroad ties are members generally laid transverse to the rails and on which the rails are supported and fixed, to transfer the loads from rails to the ballast and sub grade below, and to hold the rails to the correct gauge. Synthetic, i.e., plastic, railroad ties that are used to couple the rails of a train track are known in the art. Known synthetic railroad ties include U.S. Pat. Nos. 4,083,491; 6,021,958; and 7,204,430. These ties are said to outlast the classic wooden tie, being resistant to environmental stress, while otherwise exhibiting properties similar to their wooden counterparts in terms of damping impact loads, lateral stability, and sound absorption. Regrettably, these ties suffer from one or more disadvantages such as high cost, instability during installation, and difficult installation on a grade. Therefore, there is a need for a reinforced railroad tie that is lower cost, has greater stability during installation, and is easier to install on a grade.

SUMMARY

According to the present invention, there is provided a tie for use on a railway that satisfies the above-identified needs for a reinforced railroad tie. The railway tie according to the present invention is formed at least partially of polymeric material and may be manufactured at a lower cost than other known polymeric railway ties. The tie according to the present invention is weighted such that it has greater stability during installation and is easier to install on a grade.

In one embodiment of the present invention, a tie having a substantially rectangular prismatic body formed at least partially of polymeric material is provided. The body has a horizontal axis, a vertical axis, a top surface, and a bottom surface, and preferably, has substantially no external apertures. Encapsulated within the body is an elongated reinforcement. The reinforcement has a horizontal axis, a vertical axis, a top section having a top surface, a bottom section having a bottom surface, and a support section connecting the top section and the bottom section. The bottom section of the reinforcement has a greater weight, and cross-sectional area, than the top section of the reinforcement. Preferably, the reinforcement is centrally encapsulated within the body such that the vertical axis of the reinforcement is substantially parallel with the vertical axis of the body, and the horizontal axis of the reinforcement is substantially parallel with the horizontal axis of the body. Also preferably, the bottom surface of the bottom section of the reinforcement has a substantially flat planar surface.

In another embodiment according to the present invention, there is provided a track for a vehicle. In one embodiment the track comprises at least one rail, a plurality of elongated ties supporting the rail, and a fastener for holding the rail to the ties. According to this embodiment, at least one tie a body formed at least partially of a polymeric material and an elongated reinforcement encapsulated within the body as described herein. In one preferred embodiment, the track is on a bridge, in another preferred embodiment, the track is on a grade.

FIGURES

These and other features, aspects and advantages of the present invention will become better understood from the following description, appended claims, and accompanying figures where:

FIG. 1 illustrates a top view of a railway tie comprising a reinforcement encapsulated inside a body, in accordance with the present invention;

FIG. 2 illustrates a side view of a railway tie comprising a reinforcement encapsulated inside a body, in accordance with the present invention

FIG. 3 is a perspective illustration of a railway tie comprising a reinforcement encapsulated inside a body, in accordance with the present invention;

FIG. 4 is a cross sectional illustration of a railway tie comprising a reinforcement encapsulated inside a body, in accordance with the present invention; and

FIG. 5 is a cross sectional illustration of a reinforcement comprised of a rail section, in accordance with the present invention.

DESCRIPTION

Most conventional ties are made of very strong hardwood timbers, which are very scarce, expensive to produce, and susceptible to decay. Degradation of a railway tie, also known as a “sleeper”, can lead to instability of the railway system which they support, and in turn lead to decreased safety of the rails. The present invention provides a railway tie that is strong, easily installed, and more durable than a traditional wooden tie and is particularly adapted for use as a bridge tie or installed on a grade. The railway ties according to the present invention in general have a body formed at least partially of polymeric material which has substantially no external apertures and a reinforcement which is totally encapsulated within the body. The ties are configured to provide sufficient strength to withstand the tensile, compression, shear, and torsion forces and bending moments that are exerted by a heavy load.

The encapsulation of the reinforcement structure within the polymeric body in accordance with the present invention contributes to the longevity of the ties by protecting the metal from corrosive intrusions. The reinforcement structure provides at least a substantial portion of the structural strength, integrity, and stability. In other words, the reinforcement structure functions to provide the structural core to resist bending and shear loads. The polymeric body casing provides the bulk of the mass needed to which other members can be affixed, non-limiting example of which are rails and spikes, to allow the encapsulated structure to function as tie. The casing also provides a non-conductive mass to prevent an electrical current from passing from one steel rail to another (prevents cross circuiting), if the tie is used in as a railway cross tie. It is an industry standard practice to use the steel rails on a railway to send electrical signal to traffic control systems.

According to the present invention, the reinforcement is proportioned such that the bottom section of the reinforcement has a greater weight than the top section of the reinforcement, and is generally proportioned such that the reinforcement stands upright without support, i.e., is freestanding. Preferably, the bottom section of the reinforcement has a substantially flat bottom. The proportions of the reinforcement lead to greater stability of the reinforced tie during installation, and ease of installation of the reinforced tie on a grade. Preferably the reinforcement is a recycled or “scrap” railway section. This substantially lowers the cost of producing the reinforced railway tie.

In one embodiment, the present invention is a tie for use on a railway. Referring now to FIG. 1, FIG. 2, FIG. 3, and FIG. 4, a reinforced railway tie 10 according to the present invention is shown. FIG. 1 illustrates a top view of a railway tie comprising a reinforcement encapsulated inside a body. FIG. 2 illustrates a side view of a railway tie comprising a reinforcement encapsulated inside a body, and FIG. 3 is a perspective illustration of a railway tie comprising a reinforcement encapsulated inside a body. FIG. 4 is a cross sectional illustration of a tie comprising a reinforcement encapsulated inside a body. Preferably, a typical railroad tie 10 according to the present invention has a length of about six feet to about fourteen feet, a width from about six to about sixteen inches, and a depth from about six to about sixteen inches. It generally is in the shape of a rectangular or square prism, i.e., a vertical cross-section through the railroad tie 10 yields a rectangular or square.

The tie 10 comprises a body 12 formed at least partially of polymeric material. The body 10 has a horizontal axis 14, a vertical axis 16, a top surface 18, and a bottom surface 20. Preferably, the body has substantially no external apertures.

As shown in FIG. 1, FIG. 2, and FIG. 3, within the body 12, is an elongated reinforcement 22 which is encapsulated within the body 12. The reinforcement 22 has a horizontal axis 24, a vertical axis 26, a top section 28 having a top surface 30, a bottom section 32 having a bottom surface 34, and a support section 36 connecting the top section 28 and the bottom section 32. As shown in FIGS. 3 and 4, the reinforcement is proportioned such that the bottom section 32 has a greater weight than the top section 28. It is preferable, but not required that the bottom surface 34 of the bottom section 32 is a substantially flat planar surface. Also preferably, the top section 28 and the bottom section 32 are proportioned such that the reinforcement is upright standing without support.

As shown in FIGS. 3 and 4, the reinforcement 22 is centrally encapsulated within the body 12 such that the vertical axis 26 of the reinforcement 22 is substantially parallel with the vertical axis 16 of the body 12, and the horizontal axis 24 of the reinforcement 22 is substantially parallel with the horizontal axis 14 of the body. In addition, in the reinforced tie 10 according to the present invention, the bottom surface 34 of the reinforcement 22 is a substantially flat planar surface 34 and the horizontal axis 24 of the reinforcement 22 is substantially parallel with the horizontal axis 34 of the body 12.

The reinforcement 22 according to the present invention has a horizontal length 38 from about 6 feet to about 14 feet and a vertical height 40 from about 5 inches to about 8 inches. However, the length of the reinforcement 22 will vary depending on the length of the tie. Preferably, there is at least about two inches of body 12 encapsulating the reinforcement 22 on each side.

Preferably, the reinforcement 22 is a rail section, and more preferably a scrap rail section. The use of scrap rails as the reinforcement 22 in the tie 10 of the present invention lowers the cost of producing the ties. Rail sections, 115 RE; 119 RE; 132 RE; 133 RE; 136 RE; 140 RE and 141 RE, as designated in the AREMA Manual for Railway Engineering, American Railway Engineering and Maintenance-of-Way Association, copyright 2006, Part 1, Design, may be used in the present invention.

Referring now to FIG. 5, a cross sectional illustration of a reinforcement 22 comprised of a rail section, in accordance with the present invention is shown. According to the present invention, the area of a square inch section of the reinforcement 22 is from about 11 inches to about 14 inches, the vertical height 40 of the reinforcement is from about 5 inches to about 7 inches, the width 42 of the bottom section 32 of the reinforcement 22 is from about 5 inches to about 8 inches, and the width 44 of the top section 28 of the reinforcement 22 is from about 2 inches to about 4 inches. According to the present invention, the dimensions and area of a square inch section of the rail sections 115 RE; 119 RE; 132 RE; 133 RE; 136 RE; 140 RE and 141 RE, as referenced in the AREMA Manual for Railway Engineering, FIGS. 4-1-3 through 4-1-9 are shown in Table 1.

TABLE 1 Rail Section¹ 115 RE 119 RE 132 RE 133 RE 136 RE 140 RE 141 RE Rail Area (square inch) Top Section (28) 3.9 4.3 4.4 4.7 4.8 5.0 5.4 Support Section (36) 3.0 3.0 3.6 3.5 3.6 3.7 3.5 Bottom Section (32) 4.3 4.3 4.9 4.9 4.9 4.9 4.9 Whole Rail 11.2 11.6 12.9 13.0 13.3 13.6 13.8 Vertical Height (40) of 6.6 6.8 7.1 7.1 7.3 4.0 7.4 Rail (inches) Top Section Width (42) 2.7 2.6 3.0 3 2.9 3.0 3.1 (inches) Bottom Section Width 5.5 5.5 6.0 6.0 6.0 6.0 6.0 (44) (inches) ¹AREMA Manual for Railway Engineering, American Railway Engineering and Maintenance-of-Way Association, copyright 2006, Part 1.

The tie according to the present invention may be prepared by placing a reinforcement 22 inside a mold to be encapsulated within the body 12 using injection-molding techniques. The interior chamber of the mold may be configured to be commensurate with the required parameters of a typical tie. The reinforcement 22 is intentionally placed in the mold cavity to allow extruded material to evenly be distributed on all sides of the reinforcement 22. As illustrated in FIG. 3 and FIG. 4, the reinforcement 22 is placed in the mold (not shown) so that when the material encapsulates it, the reinforcement 22 is fixed in the midpoint of the encapsulating body 12, i.e., it is centrally located within the body 12. However, the position of the reinforcement 22 within the body 12 may be varied, as will be understood by those of skill in the art by reference to this disclosure.

The body 12 of the tie 10 is formed from a polymeric material using an injection molding technique and equipment similar to that for die casting, in that a precision mold of desired shape is clamped shut, and melted material (for example, from palletized plastics) is forced into the cavity between the mold and the reinforcement 22 that is placed inside the mold. The exemplary palletized plastic material is fed into a heated chamber, or barrel, by a large, slowly rotating mechanism, and is melted. When a sufficient quantity to fill the mold cavity has been prepared, the rotating mechanism is moved axially under high pressure to extrude the melted material into the mold cavity. Some molds may have channels through which coolant is circulated to remove heat and to chill the plastics. When the plastic has cooled sufficiently, the mold is unclamped (or opened), and the molding is either forced out by strategically located ejectors or simply forcefully removed (depending on the type of mold being used.) During cooling and removal, material for the next part is plasticized within the barrel, ready for the cycle to be repeated. For further details of this process and suitable materials for the polymeric body, see U.S. Pat. Nos. 6,244,014 and 6,412,431, all to Barmakian, the entire disclosures of which are incorporated herein by reference. A preferred plastic material for the body 12 is recycled polyethylene that contains at least 96% to 98% polyethylene film for lubricity and flexibility.

FIG. 6 is an exemplary cross-sectional perspective illustration of a track 50 according to the present invention, which is comprised of a metallic reinforcement 22 encapsulated, and preferably centrally located in all dimensions, inside a body 12. Preferably, the reinforcement is steel or steel alloy, and more preferably, the reinforcement is a scrap railway tie as described herein. The body 12 is comprised at least partially of a polymeric material, i.e., a substance made of many repeating chemical units or molecules. As illustrated in FIG. 6, the track 50 is formed by placing a tie 10 across one or more two steel girders 52 a and 52 b in a conventional manner, where the rails 54 a and 54 b are positioned such that the girder span (or length) L_(G) between the girders 52 a and 52 b is in general equal to or greater than the rail span L_(R) between the two rails 54 a and 54 b. In other words, the outer edges 55 a and 55 b of the rails 54 a and 54 b are in general near the inner top surface edges 56 a and 56 b of the girders 52 a and 52 b, with a separation distance 58 between the two edges as illustrated. In another embodiment, the tie is laid on top of a track ballast which supports and holds the tie in place and provides drainage. According to this embodiment, the ballast is a material such as stone, sand, gravel, as is known to those of skill in the art.

In general, the rails 54 a and 54 b are laid transverse to the ties and held to the tie with one or more fasteners 60, such as a cleat, a bolt, a rail spike, a rail clip, or a screwed rail attachment, or a combination thereof. The tie 10 acts as an anchor and spacer for the rails, and the tie transfers the load from the rails 54 a and 54 b to the underlying girders 52 a and 52 b or ballast. Under heavy load conditions, the tie 10 according to the present invention can withstand tensile, compression, shear, and torsion forces and bending moments.

Although the present invention has been discussed in considerable detail with reference to certain preferred embodiments, other embodiments are possible. Therefore, the scope of the appended claims should not be limited to the description of preferred embodiments contained herein. 

1. A track for a vehicle comprising: (a) at least one rail; (b) a plurality of elongated ties supporting the rail; and (c) a fastener for holding the rail to the ties, wherein at least one tie comprises: a body formed at least partially of polymeric material, the body having a horizontal axis, a vertical axis, a top surface, and a bottom surface, the top surface of the body being fastened with the fastener to the rail; and an elongated reinforcement encapsulated within the body, the reinforcement having a horizontal axis, a vertical axis, a top section having a top surface, a bottom section having a bottom surface, and a support section connecting the top section and the bottom section, the bottom section having a greater weight than the top section.
 2. A track according to claim 1 wherein the reinforcement is centrally encapsulated within the body such that the vertical axis of the reinforcement is substantially parallel with the vertical axis of the body, and the horizontal axis of the reinforcement is substantially parallel with the horizontal axis of the body.
 3. A track according to claim 1 wherein the bottom surface of the reinforcement is substantially flat, and the horizontal axis of the reinforcement is substantially parallel with the horizontal axis of the body.
 4. A track according to claim 1 wherein the body of the tie is a substantially rectangular prismatic body having a length of from about 6 feet to about 14 feet, a width of from about 6 to about 16 inches, and a depth of from about 6 to about 16 inches.
 5. A track according to claim 1 wherein the body has substantially no external apertures.
 6. A track according to claim 1 wherein the top section of the reinforcement is located proximate to the top surface of the rail.
 7. A track according to claim 1 comprising a pair of parallel rails.
 8. A track according to claim 1 on a bridge.
 9. A track according to claim 1 on a grade.
 10. A tie for use on a railway, the tie comprising: a body formed at least partially of polymeric material, the body having a horizontal axis, a vertical axis, a top surface, and a bottom surface; and an elongated reinforcement encapsulated within the body, the reinforcement having a horizontal axis, a vertical axis, a top section having a top surface, a bottom section having a bottom surface, and a support section connecting the top section and the bottom section, the bottom section having a greater weight than the top section.
 11. A tie according to claim 10 wherein the reinforcement is centrally encapsulated within the body such that the vertical axis of the reinforcement is substantially parallel with the vertical axis of the body, and the horizontal axis of the reinforcement is substantially parallel with the horizontal axis of the body.
 12. A tie according to claim 10 wherein the bottom surface of the reinforcement is substantially flat, and the horizontal axis of the reinforcement is substantially parallel with the horizontal axis of the body.
 13. A tie according to claim 10 wherein the body of the tie is a substantially rectangular prismatic body having a length of from about 6 feet to about 14 feet, a width of from about 6 to about 16 inches, and a depth of from about 6 to about 16 inches.
 14. A tie according to claim 10 wherein the body has substantially no external apertures.
 15. A tie according to claim 10 wherein the reinforcement has a horizontal length of from about 6 feet to about 14 feet, a vertical height of from about 5 inches to about 8 inches, and a width at the bottom section of the reinforcement of from about 5 inches to about 7 inches.
 16. A tie according to claim 10 wherein the top section and the bottom section are proportioned such that the reinforcement is upright standing without support.
 17. A tie according to claim 10 wherein the area of a square inch section of the reinforcement is from about 11 inches to about 14 inches.
 18. A tie according to claim 10 wherein the area of a square inch section of the top section is about 3.9 inches, the area of a square inch section of the support section is about 3 inches, and the area of a square inch section of the bottom section is about 4.3 inches.
 19. A tie according to claim 10 wherein the area of a square inch section of the top section is about 4.3 inches, the area of a square inch section of the support section is about 3 inches, and the area of a square inch section of the bottom section is about 4.3 inches;
 20. A tie according to claim 10 wherein the area of a square inch section of the top section is about 4.4 inches, the area of a square inch section of the support section is about 3.6 inches, and the area of a square inch section of the bottom section is about 4.9 inches.
 21. A tie according to claim 10 wherein the area of a square inch section of the top section is about 4.7 inches, the area of a square inch section of the support section is about 3.5 inches, and the area of a square inch section of the bottom section is about 4.9 inches.
 22. A tie according to claim 10 wherein the area of a square inch section of the top section is about 4.8 inches, the area of a square inch section of the support section is about 3.6 inches, and the area of a square inch section of the bottom section is about 4.9 inches.
 23. A tie according to claim 10 wherein the area of a square inch section of the top section is about 5.1 inches, the area of a square inch section of the support section is about 3.7 inches, and the area of a square inch section of the bottom section is about 4.9 inches.
 24. A tie according to claim 10 wherein the area of a square inch section of the top section is about 5.4 inches, the area of a square inch section of the support section is about 3.5 inches, and the area of a square inch section of the bottom section is about 4.9 inches.
 25. A tie according to claim 10 wherein the reinforcement is a rail section.
 26. A tie for use on a railway, the tie comprising: a substantially rectangular prismatic body formed at least partially of polymeric material and having substantially no external apertures, the body having a horizontal axis, a vertical axis, a top surface, and a bottom surface; and an elongated reinforcement encapsulated within the body, the reinforcement having a horizontal axis, a vertical axis, a top section having a top surface, a bottom section having a bottom surface, and a support section connecting the top section and the bottom section, the bottom section having a greater weight than the top section, and the bottom surface of the reinforcement having a substantially flat planar surface, wherein the reinforcement has a horizontal length of from about 6 feet to about 14 feet, a vertical height of from about 5 inches to about 8 inches, and a width at the bottom section of the reinforcement of from about 5 inches to about 7 inches. the reinforcement is centrally encapsulated within the body such that the vertical axis of the reinforcement is substantially parallel with the vertical axis of the body, and the horizontal axis of the reinforcement is substantially parallel with the horizontal axis of the body. 